Looking Backwards Looking Forward Exploring how proxy data
Looking Backwards, Looking Forward Exploring how proxy data provides evidence for past climatic events http: //keepingbee. org/wp-content/uploads/2012/10/Bee-pollen-supplements 1. jpg
Write down 3 observations for the cartoon. Observations are what you can detect with your five senses.
Student Responses • …
• Observation is what you can detect with your five senses Observation: The fish is holding a long object. Observation: There is a hole in the container. Observation: The fish’s eyes are wide. • Inference is a conclusion reached based on evidence (including observations) and reasoning. Inference: There fish is holding a baseball bat. Inference: The fish hit a baseball through the glass bowl. Inference: The fish is surprised and worried.
Examine your initial ‘observations’. Are any of them inferences? Label any that are inferences, not observations.
Do you think scientists make observations and inferences like you did? Why do they make observations and inferences? • Scientists use observation and inference to understand how the world works and make sense of scientific phenomena.
Today you will be working as a paleoclimatologist to explore what the Earth’s past climates were like. A paleoclimatologist is a scientist who studies past climates. What was the climate like in the Anacostia watershed over the past 12, 500 years?
What does this video show? https: //youtu. be/g. EFFe. AA 3 MN 4
Weather and Climate are not the same thing • Weather is what happens on a short-term basis • Climate is the long-term average of weather Climate is what you expect, weather is what you get!
The video showed evidence that the earth has been warming since 1884.
How do scientists know what the earth was like in the past if they weren’t around to see it or if there are no records? Do a think-pair-share with someone sitting near you and discuss this question.
Student ideas • … How do scientists know what the earth was like in the past if they weren’t around to see it or if there are no records?
How do scientists know what the earth was like in the past if they weren’t around to see it or if there are no records? Scientists make inferences based on observations.
Proxy Data for Climate Proxy data are reserved physical characteristics of an environment that serve as indirect ways of getting information about a past environment. Can you think of sources scientists might use as proxy climate data?
Proxy Data for Climate Preserved physical characteristics of an environment that serve as indirect ways of getting information about a past environment. Sediment from lakes and ocean contains lots of clues about past climate in the forms of fossils and chemicals. http: //www. nps. gov/lake/lear n/nature/images/Sediment. Core. jpg http: //www. bibliotecapleyades. net/imagenes_ciencia/aster oids_comets 70_01. jpg Ice cores can tell scientists about temperature, precipitation, atmospheric conditions, oceanic activity and wind patterns. Data from coral skeletons provide information about water temperature during the time the coral was growing https: //www. ncdc. noaa. gov/news/what-are-proxy-data http: //www. thenakedscientists. com/forum/in dex. php? topic=12824. 0 Preserved pollen grains that were produced by plants thousands of years ago can tell scientists about past climate conditions. http: //www. treeringpens. com/tree-ring-science http: //earthobservatory. nasa. gov/Feat ures/Paleoclimatology_Close. Up/Image s/coral_core_drilling. jpg / Because climate conditions influence tree growth, patterns in tree-ring widths, density, and isotopic composition reflect variations in climate.
Why are data important in science?
Why are data important in science? • Scientists rely on data to provide evidence to support their claims. Data and evidence are critical in science.
Form expert groups for background research • What is pollen and how is it distributed? • What are sediment cores and how are they used by scientists? • How do plant communities reflect local climate and climate change? • How are proxy data used to learn about past climate?
Placemat Graphic Organizer Climate Proxy Data Sediment Cores Pollen Plant Communities and Climate How can we infer past climates from the plants that were growing in an area?
Expert Groups Pollen Plant Communities and Ecosystems … … Sediment Cores Proxy Data … …
Form sharing groups to answer Challenge Question How can we infer past climates from the plants that were growing in an area? Make sure to include information in your answer from each of the topics represented by your experts on: • • Pollen Plant Communities Sediment Cores Proxy Data
Sharing Groups Group 1 … Group 2 Group 3 Group 4 Group 5 Group 6 … … …
How can we infer past climates from the plants that were growing in an area? https: //researcherridge 201 4. wordpress. com Frode Jacobsen Dartmouth Electron Microscope Facility, Dartmouth College https: //sites. google. com/site/roxym 3 04/_/rsrc/1397797367372/honbiology-units/unit-9 --ecolosystems/tropical-rainforest- G. Brush Plant Communitie s https: //biomesfirst 10. wikispaces. com/T emperate+Deciduous+Forest+Home https: //biomesfirst 10. wikispaces. com/Temp erate+Deciduous+Forest+Home
What was the climate like in the Anacostia Watershed over the past 12, 500 years? • Forested floodplain on Indian Creek, a tributary of Anacostia River in Prince George’s County, Maryland • Area is currently 100 acres of wetland Click on image above to access interactive Google map
Getting the sediment core sample • Go into the field and drill a sediment core sample • Bring sample back to lab and cut into thin slices, each representing a piece of geological time • Chemically treat each sample so to filter out the very tiny grains of pollen • Identify each pollen grain so they could determine which types of plant were present thousands of years in the past This end was closest to surface http: //www. amssamplers. com/media/catalog/category/multi-stagesludge-sampler-use-2. jpg 3, 400 – 6, 000 11, 000 ybp 11, 000 – 12, 500 ypb http: //schmidtocean. org/wpcontent/uploads/2012 -11 -09 -dnmpushcoreupclose-768 x 512. jpg http: //www. lpc. uottawa. ca/resou rces/Pollen%20 heavy%20 liquid%2 0 pics/vortex. bmp http: //iansa. eu/papers/IANSA-2012 -02 -bernardova-webresources/image/5609. png Data adapted from Yuan, 1995. 0 – 340 ybp This end was the deepest. https: //ferrebeekeeper. files. word press. com/2010/04/pollenheader. jpg
Examining a 12, 500 year pollen sediment core This end • Slice 4: ~340 ybp was closest This end of the sediment core was closest to the surface. 4 3 to the surface What does “ybp” stand for? • Slice 3: ~3, 000 ybp • Slice 2: ~10, 000 ybp • Slice 1: ~11, 900 ybp 2 1 This end of the sediment core was the deepest.
You’re going to examine a model of a sediment core. Dartmouth Electron Microscope Facility, Dartmouth College 1 bead represents a pollen grain from a specific taxon (type of plant) in your sample.
What was the climate like in the Anacostia Watershed over the past 12, 500 years? • Forested floodplain on Indian Creek, a tributary of Anacostia River in Prince George’s County, Maryland • Area is currently 100 acres of wetland
Collecting Pollen Data • Each group is being assigned a sample from one slice of the sediment core: • • Slice 4: ~340 ybp Slice 3: ~3, 000 ybp Slice 2: ~10, 000 ybp Slice 1: ~12, 500 ybp • What type of information will you need to collect? As a group, create a table on your white board where you will write you data. • Sort though your sediment sample for pollen, and fill in your data table on your white board • Calculate the percentage of each type of pollen in your sample • Add your percentages of pollen to the class data set 4 3 2 1
Class Data Table. If more than one group collected data for a time period, record the average of the two groups. Bead Color Pollen Taxa red Alder white Birch yellow Fir green Hemlock black Oak brown Pine blue Ragweed purple Sedges orange Spruce pink Viburnum % Pollen ~340 ybp % Pollen ~3, 000 ypb % Pollen ~10, 000 ypb % Pollen ~12, 500 ypb
Graphing the Data • Make a graph of the percentage of each pollen species for each time period (you will be making 4 graphs • In order to facilitate comparison later make sure to do the following: • Arrange the taxa along the x-axis in alphabetical order • Leave a space for all taxa, even if none were counted • Use a common scale (0% – 50%) on the y-axis
What do you need to do next to be able to answer your question? What was the climate like in the Anacostia Watershed over the past 12, 500 years?
Data analysis and interpretation Look for patterns in your data to answer the question. • Use the Plant Characteristics Table if you need more information about the preferred climate of each taxon. • Consider the following: • Which taxon are most represented in your sample? • Which taxon are NOT represented in your sample? • Are the percentages of specific taxa going up or down through time? • What type of climate does each taxon do best in? Wet? Dry? Cold? Hot? What was the climate like in the Anacostia Watershed over the past 12, 500 years?
Scientific Argument • Each person in your group needs to write a scientific argument (a claim, supported by evidence and reasoning) about what the climate was over the past 12, 500 years in the Anacostia watershed. • You can ask your group members for help, but you must write your own scientific argument. Claim: Answer to the question What was the climate like in the Anacostia watershed over the past 12, 500 years? Evidence: The data that support your claim. Must be appropriate and sufficient. Reasoning: Explains how the data support the claim. Includes scientific principles.
Scientific Argument Peer Review • You will be paired up with a person from another group. • You will compare your responses and critique your own scientific explanations. • Use the rubric provided to assess your CER.
Scientific Argument Peer Review • Using the feedback from your peer review session, revise your scientific explanation about what the climate was like in this region over the past 12, 500 years.
An important aspect of science is identifying and explaining patterns in nature. Explain why this is important for scientists to do, using an example from your climate investigation.
An important aspect of science is identifying and explaining patterns in nature. Explain why this is important for scientists to do, using an example from your climate investigation. Science assumes that objects and events in natural systems occur in consistent patterns that are understandable through measurement and observation. By studying these patterns, scientists can understand how the natural world works. By understanding past patterns of climate change, scientists are able to develop a better understanding of current causes of climate change.
Does all science require controlled experiments? Provide specific examples from this activity to support your answer.
Does all science require controlled experiments? Provide specific examples from this activity to support your answer. Not all scientific knowledge comes from controlled experiments. For example, in astronomy scientists cannot manipulate planets or star but they are still able to make observations and inferences and learn about how the universe works. In the work we have been doing with pollen and climate, we did not create a controlled experiment. Rather, we made observations and inferences of data from different time periods to infer what past climates were like.
Climate Change Past and Present • Read the passage on pages S 7 -S 8 in your student hand -out. • Answer the Discussion Questions
Why is our climate changing so quickly now?
What are the effects of the fast rate of climate change we are currently experiencing?
How would you respond if you heard someone say… I heard that the climate has changed before and this current climate change we are talking about is just like that. So we don’t have to be worried. It’s the same thing.
How is current climate change different than past climate change? • Our climate is changing at a much faster rate than even before! • This change is due to humans releasing CO 2 into the atmosphere. • This is a problem because a changing climate results in: • Increasing sever weather events • Affects how we grow and produce food
What can we do about Climate Change? Reduce our Carbon Footprints by: • Using less energy • Drive less • Use less electricity • Reduce, reuse and recycle • Develop alternative sources of fuel • • Wind Solar Algae-based fuels Etc….
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